Screw-nail



(No Model.) H. DUNHAM.

SCREW MIL. No. 266,276. Patented 0011.24, 1882.

N. PETERS. Phobhmcgnphar. Washin ton. me,

Unrrn- Starts PATENT rrice.

HENRY DUNHAM, O F ABINGTON, MASSACHUSETTS.

SCREW-NA|L.

SPECIFICATION forming part of Letters Patent No. 266,276, dated October 24,, 1882.

I Application filed November 19, 1881. (No model.)

To all whom it may concern Be it known that I, HENRY DUNHAM, a citizen of the United States, residing at Abington, in the county of Plymouth and State of Massachusetts, have invented certain new and useful Improvements in Screw-Nails; and I do hereby declare that the same are fully described in the following specification and illustrated in the accompanying drawings.

This invention relates to improvements in screw-nails, and it is carried out as follows, reference bring had to the accompanyingdrawings, on whieh Figure 1 represents a plan view of the sheetmetal strip from which the nail-blanks are cut off. Fig. 2 represents a side elevation of a nail-blank after being headed, and Fig. 3 represents a side elevation of the headed nailblank after being twisted, as will hereinafter be more fully shown and described.

In Fig. 1, (t represents a strip of sheet metal, which is cut up into nail-blanks a a a, as shown in the righthand part of said Fig. 1. The nail -blanks a a are afterward headed and provided with a head, 1), (shown in Fig. 2.) and forming a nail having a tapering shank, b, terminating above as ahead, I), as represented in said Fig. 2. The cutting offof the nail-blanks a a from the sheet-metal strip a and afterward heading each of said nail-blanks may be done in any of the ordinary tack-machines, or by means of special machinery for this purpose. if so desired. After the nailblank is headed, as shown in Fig. 2, its shank is twisted to form a screw-thread, 1), (shown in Fig. 3,) which screw-thread may extend from the point 12' up to or more or less toward the under side of the head I), as may be desired, according to the nature of the material for which the screw-nail is designed. In this manner I produce a screw-nail having a twisted shank, I), combined with a head, I), in its upper end, as shown in Fig. 3, and such a screwnail is very useful for pegging boots and shoes as well as for uniting leather-work of any kind. It may also to advantage be used for wood works of any kind where nails or screws have heretofore been used to secure different parts of the work.

The twisting of the shanks of the nails may be done by hand or by'means of special machinery for this purpose.

The point b of the nail may be made more or less sharp, according to the nature of the material for which it is intended.

For leather-work it is desirable to clinch the nail, and its point b is therefore made'to turn back into the leather to clinch when used for this purpose.

This my improved screw-nail is preferable to other kinds heretot'ore made on account of its having a head, I), in combination with its twisted shank b, by which arrangement dit ferent parts of leather or other material can be united firmly together without exerting so strong a blow in driving it as would be the case if the screw-nail were not provided with head. In the latter case ahead, it made at all, is made in riveting the nail when in the work or articles to be united.

I prefer to make the point of this improved screw-nail of a chisel shape, in order to enable it to be properly clinched in uniting soles of boots or shoes or for other leather-work.

By this my improved method of making screw-nailsIproducesuch with sharpand cleancut edges, which are particularly well adapted for uniting soles of boots and shoes, as they may be driven with great ease and with less resistance than other screw-nails, and when driven will retain their hold in the material better and firmer. A nail made by my improved method can also be made at a less expense than others having a head and sczewtwisted shank.

Iam aware that ordinary nails have heretol'ore been made by cutting them from a strip of sheet metal, and I desire to state that I do not claim broadly such a method as my invention. Neither do I claim broadly to twist the shanks of nails, as Iain aware that forged or rolled nails have afterward been twisted; but

What- I desire to secure by Letters Patent, and claim, is-- A nail having a head, I), the shank b, tapering and twisted throughoutits length, and the clinching-point 12', substantially as shown, and for the purpose set forth.

In testimony whereof I have aflixed my signature in presence of two witnesses.

HENRY DUNHAM. w Witnesses:

ALBAN ANDREN, HENRY D. BRISTOL. 

